Because of its advantages such as small size, inexpensiveness and noise-free operation, a so-called ink jet recording apparatus which is adapted to jet a liquid or molten solid ink through a nozzle, slit, porous film or the like against paper, cloth, film or the like to effect recording has been extensively studied. In recent years, besides black monochromatic printers capable of recording on so-called ordinary paper such as report blank form and duplicating paper with a good print quality, many printers capable of recording in all colors have been commercially available and thus played an important role in the art of recording apparatus.
An ink for use in these ink jet recording apparatus is mainly composed of a solvent, a coloring material and additives. An ink for ink jet recording method has the following requirements:
(1) It must provide a high resolution, high density uniform image which does not run or fog on paper; PA1 (2) When dried at the tip of the nozzle, it must cause no nozzle clogging, providing invariably good jetting response and stability; PA1 (3) It must be easily dried on paper; PA1 (4) It must provide an image with a good fastness; PA1 (5) It must have a good storage stability.
In particular, various measures have heretofore been devised for the requirements (1) and (3). For example, JP-A-63-132083 (The term "JP-A" as used herein means an "unexamined published Japanese patent application") discloses a method which comprises the use of 10% and 30% solutions of a solid substance such as polyethylene glycol, aliphatic acid and salt thereof having a molecular weight of not less than 300, the viscosity ratio of which is 1:3 or more, to provide a thickened ink which causes less bleeding. U.S. Pat. No. 5,133,803 discloses a method for inhibiting bleeding which comprises the use of a high molecular colloidal substance having a molecular weight of not less than 10,000 such as alginic acid, carboxymethylcellulose and carrageenan. JP-A-6-136306 discloses a method which comprises using a high molecular substance having a molecular weight of from 3,000 to 50,000 to define the surface tension and viscosity of the ink to a predetermined range that can accomplish both the desired fixability and prevention of bleeding. However, these inks disclosed are disadvantageous in that they provide uneven image, dry slowly, tend to clog the orifice or, if used in a recording process which comprises the action of heat energy to jet the ink, cause an output drop. These problems are particularly remarkable in a high resolution small drop print ink jet recording method.
Further, JP-B-60-34992 (The term "JP-B" as used herein means an "examined Japanese patent publication"), JP-A-62-11781, JP-B-62-13388, JP-A-1-230685, JP-A-3-41171 disclose a method which comprises the addition of a surface active agent, a polyvalent alcohol derivative or the like to enhance the dryability of the ink on paper. However, the inks disclosed in these patents are disadvantageous in that they tend to run on paper and penetrate into paper, causing the drop of image density. Thus, no inks which provide a highly color-developed image with a good print quality on ordinary paper, dry rapidly on paper and can be jetted with a high reliability have been found.